1. Technical Field
This invention relates generally to semiconductor and manufacturing methods thereof, and more particularly, but not exclusively, to a package having an RFID chip positioned between a pair of semiconductor substrates and a method of manufacture.
2. Description of the Related Art
A wafer undergoes many manufacturing processes to form many thousands of devices on it. During and after the manufacturing processes, the wafer is subjected to a series of testing procedures to confirm functionality of the devices, determine speed of operation, and assure quality and reliability. Data of the manufacturing processes and testing procedures are collected and stored in a database that identifies the wafer and each die on the wafer. Such data are stored in correlation with the wafer identification so that the process history and testing results of the devices on the wafer can be tracked as the wafer moves through the process line and toward packaging.
After the wafer is completed, a wafer probe test is carried out in which each die on the wafer is tested for functionality. The functional die may be tested for operational characteristics, and subject to a bin sort, based on various properties, such as memory speed, CPU clock speed, and the like.
After dicing, the non-functional die are discarded and the functional die are sorted into the respective bins, with new identification numbers assigned based on their bin sort properties.
For some types of devices, only a functional test is performed and the die are sorted into two groups: functional and non-functional, and a more detailed bin sort is not carried out.
According to one prior art process, when a wafer is tested at a probe station after it is manufactured, the data is stored in a computer memory as a wafer map that identifies which die on the wafer are defective and which are operational. If the operational die are being sorted into bins, based on such features as memory speed, clock speed, or other factors, this information is also stored on the wafer map. When the wafer is diced at the back-end packaging, each die is assigned a new part number based on the bin sort that was determined. The wafer map is read to identify which dice are to be discarded and which are to be sorted into the different bins. Since the die are assigned new numbers based on the bins sort, the wafer map is no longer useful and tracking the die based on the wafer and lot is no longer carried out.
When the wafers are sawed into dice and packaged into individual units during the packaging process, sometimes called the back-end manufacturing process, the historical wafer information related to each singulated die cannot be tracked any more due to absence of linking between the front-end manufacturing process and the back-end packaging manufacturing process. If a packaged die is later determined as defective or unreliable, it would be desirable to know the full process history and testing results of the die to help track down the problem.